docs: def _checksum(cls, line):
          """Compute the checksum of a full line
  
          Args:
              line (str): Line to compute the checksum from
          Return:
              int: Checksum (modulo 10)
          """
          tr_table = str.maketrans({c: None for c in ascii_uppercase + "+ ."})
          no_letters = line[:68].translate(tr_table).replace("-", "1")
          return sum([int(l) for l in no_letters]) % 10